Jointing Sled for the thickness planer built from acrylic and aluminum
The objectives for this jointing sled:
1. Weather resistant / corrosion resistant (waterproof) to maintain the flatness / straightness indefinitely.
2. Extremely slim to preserve the maximum stock height as close as possible to the thickness planer's original capacity.
3. Fast and easy to setup / adjust to make it feasible for the frequent use.
4. No special tools or materials required in order to use it (no wedges, no hot glue sticks and hot glue gun, no double sided tapes, no sand paper etc)
5. No troublesome cleanup required (removing the hot glue or sticky tapes, changing worn out sandpaper
6. Very accurate and able to maintain the accuracy over long period = indefinitely.
With the above very demanding objectives in mind, I came up with the very sleek idea and design, and I built such a jig.
The base material is 19 mm cast acrylic sheet (the best flatness available on the market), reinforced with the 3mm thick aluminum angles. All bolts and nuts are stainless steel. Anti-vise used for clamping the wooden piece is made from 3/4 inch aluminum square bar with the M8 stainless steel clamping bolts.The front stop block is implemented using the stainless steel 6 mm flat grub / set screws, protruding above the acrylic surface from the stainless steel threaded inserts (M9 external / M6 internal thread). The grub screws level can be adjusted from the underneath of the sled using the 3 mm allen key.
The matrix of the 8mm holes threaded to 9mm, to embed the M9 external threaded inserts, is spaced 4 inches apart in 3 rows, 2 and 4 inches apart.
Such a modular approach allows any jigs / attachments in the future to be linked to the sled, as long as they follow the proposed mounts spacing..
The cupped or twisted wooden boards can be supported by the 2 lines::
2 inch apart (narrow stock)
4 inch apart (medium stock)
or 3 lines (2 inch + 4 inch apart) (wide stock).
The transparency of the acrylic makes it easy to spot the cupped or twisted areas, and adjust the grub screws level underneath accordingly. Or we can turn the grub screw until the piece is lifted slightly, and then back off half a turn.
As the piece travels under the planer's rollers, and is pushed down, the cup or twist would be supported by the protruding flat head grub screws. This allows to cut the cup or twist, mimicking the primary function of the jointer.
COPYRIGHT AND FAIR USE NOTICE
Should you make use of my design or make a new / better design derived from mine, kindly acknowledge the source and the author.
Bookmarks